Enforce that required attributes can't be set to None in CRUD Update

The `required` parameter attribute didn't distinguish between cases
where the parameter is not given and all, and where the parameter is
given but empty. The case of updating a required attribute couldn't
be validated properly, because when it is given but empty, validators
don't run.
This patch introduces a new flag, 'nonempty', that specifies the
parameter can be missing (if not required), but it can't be None.
This flag gets added automatically to required parameters in CRUD
Update.

1 files changed, 5 insertions, 4 deletions

diff --git a/ipalib/parameters.py b/ipalib/parameters.py
index b1525b4d5..48155daf9 100644
--- a/ipalib/parameters.py
+++ b/ipalib/parameters.py
@@ -558,9 +558,9 @@ class Param(ReadOnly):
         else:
             value = self.convert(self.normalize(value))
         if hasattr(self, 'env'):
-            self.validate(value, self.env.context)  #pylint: disable=E1101
+            self.validate(value, self.env.context, supplied=self.name in kw)  #pylint: disable=E1101
         else:
-            self.validate(value)
+            self.validate(value, supplied=self.name in kw)
         return value
 
     def kw(self):
@@ -820,15 +820,16 @@ class Param(ReadOnly):
             error=ugettext(self.type_error),
         )
 
-    def validate(self, value, context=None):
+    def validate(self, value, context=None, supplied=None):
         """
         Check validity of ``value``.
 
         :param value: A proposed value for this parameter.
         :param context: The context we are running in.
+        :param supplied: True if this parameter was supplied explicitly.
         """
         if value is None:
-            if self.required:
+            if self.required or (supplied and 'nonempty' in self.flags):
                 if context == 'cli':
                     raise RequirementError(name=self.cli_name)
                 else: